The invention relates to a weaving machine with a weft monitoring insertion system for a plurality of different weft threads a weft monitoring insertion system for a plurality of different selected and non-selected weft threads. It also relates to a method for the operation of a weaving machine of this kind.
A rapier weaving machine is known from EP-A 0 816 545 (=T.964) with an apparatus which recognises incorrectly inserted weft threads. This weaving machine with a weft monitoring insertion system is provided for the manufacture of cloths (fabrics) into which a large number of different weft threads are woven. On account of restricted space conditions in the region of the thread server there are, in addition to correctly inserted threads, occasionally also co-moving weft threads which are also inserted by the weft insertion member without an intended cause. Therefore it is proposed in the named specification to provide, in addition to a first weft thread monitor, a second weft thread monitor for the monitoring of co-moving weft threads.
The first weft thread monitor can be used to measure the thread tension force. As a result of the measurement values obtained with a thread monitor of this kind, thread brakes of the insertion system can be set in such a manner that a situation is avoided in which damaging thread tensions are exceeded.
For certain cloths it is necessary that two or more threads be inserted into the shed at the same time by the weft insertion member. A multiple weft insertion of this kind (or double insertion in the case of two weft threads inserted together) makes the manufacture of an impeccable cloth even more difficult. The object of the invention is now to create a weaving machine with an insertion system by means of which, on the one hand, the weft thread tension can be regulated and by means of which, on the other hand, a multiple weft insertion is also possible. In this only one thread monitor is to be used for the tension monitoring of correctly inserted weft threads. Faulty insertions through co-moving threads should be avoided by means of the use of at least one further thread monitor.